No doubt weight loss is a part, but it's been very obvious from the pattern of weight loss and health improvement, that the weight loss isn't causing the health improvements nearly as much as the healthier habits are causing both the health improvements and the weight loss.
It's why I think it's so important to tell people, "even if you are convinced you can't lose weight, you can still benefit from healthy activity and diet changes."
For me it was key to lose weight by not trying to lose the weight, but by choosing habits that would improve my health even if I didn't lose.
I'm willing to focus more energy on losing weight, but I still always have to remember my true priority, because when I make it about numbers, I lose sight of what I'm really fighting for.